What the Hamlet are they saying?

From Hamlet lines 81-119

Marcellus:

 Why do we work all night on watching the land And spend all day arming ourselves and making weapons? Why do shipwrights work even on Sunday at their toilsome jobs, working day to night. Who can explain it to me?

 Horatio:

I can explain. The rumors are that the previous king whose ghost was just before us was, by challenged by Fortinbras of Norway to combat. King hamlet killed Fortinbras in a sportsmanlike manner, and as a result was made the ruler of Fortinbras’s lands, however part of this territory was returned to Fortinbras’s family. Fortinbras’s son who was full of anger gathered a group of outlaws to recover his fathers lost lands. I believe that is the reason why we are on guard duty here.